Table 2.

Risk factors for progression from URTI/possible LRTD to probable/proven LRTD (N=476)

	Univariable analysis			Multivariable analysis
	HR	95% CI	P Value	HR	95% CI	P Value
Transplant year
1990–2000	1.00
2001–2011	0.55	0.3–0.9	0.028
Cell source
PBSC	1.00
BM or CB	1.93	1.1–3.4	0.019
ATG use before PIV infection
No/More than 6 months	1.00			1.00
Within 6 months	2.27	1.1–4.5	0.025	1.89	0.9–3.8	0.09
PIV type
PV-1, 2, 4	1.00			1.00
PV-3	4.55	0.3–14.3	0.011	3.57	1.1–11.1	0.032
Co-pathogen
No	1.00			1.00
Upper respiratory tract	0.85	0.3–2.4	0.76
Blood	3.00	1.1–8.3	0.035	3.21	1.1–9.0	0.027
White blood cell count
> 1000/μL	1.00
≤ 1000/μL	2.29	1.3–4.1	0.006
Neutrophil count
> 500/μL	1.00
≤ 500/μL	2.05	1.1–3.8	0.02
Lymphocyte count
> 300/μL	1.00			1.00
100–300/μL	1.16	1.7–5.6	0.66
< 100/μL	3.25	1.7–6.1	<.001	1.79	0.9–3.6	0.10
Monocyte count
> 300/μL	1.00			1.00
100–300/μL	1.68	0.8–3.4	0.16
< 100/μL	3.96	2.1–7.5	<.001	2.22	1.2–4.2	0.011
Steroid dose before diagnosis
No	1.00			1.00
< 1 mg/kg	0.94	0.4–2.1	0.89
1–2 mg/kg	2.53	1.4–4.6	0.002	1.89	1.1–3.2	0.018
> 2 mg/kg	4.20	1.0–18.1	0.054
Steroid dose after diagnosis*
No	1.00
< 0.5 mg/kg	0.60	0.3–1.4	0.24
0.5–1 mg/kg	0.67	0.3–1.6	0.36
> 1 mg/kg	2.35	0.7–7.6	0.15
Ribavirin use*
No	1.00
Yes	2.29	0.7–7.4	0.16
Viral load in NP sample at diagnosis**	1.00	1.0–1.0	0.46

^*These variables were analyzed as time-dependent.

^**Viral load was analyzed as a continuous variable.

All variables in Table 1 were used for the univariate analysis. Co-pathogen and ribavirin use at diagnosis of URTI/possible LRTD were included in the analysis. Only variables with p < 0.05 in any analysis are shown in this table. The following parameters were also shown regardless of p values; steroid dose after diagnosis, ribabirin use.

Abbreviations: PBSC, periperal blood stem cell; BM, bone marrow; CB, cord blood; ATG, anti-thymocyte globulin; NP, nasopharyngeal